Seating and the donut

[CatShooter]

Damn if you do Damn if you don't, I was thinking of using a taper reamer?

Joe Salt

But a taper reamer cuts at the wrong end

 

[Joe Salt]

Catshooter MSC ind. has them and they look like they cutting edge is on the whole length! I think I just have to make sure of the length.

Joe Salt

 

[CatShooter]

Catshooter MSC ind. has them and they look like they cutting edge is on the whole length! I think I just have to make sure of the length.

Joe Salt

Joe... think about it... the taper reamer will cut at the mouth, but the donut is at the other end of the neck, right under the shoulder... the taper reamer will rip the neck out before it even gets near the donut...

... it's all Dunkin's fault

 

[asauer]

I recently went through this with my 300WSM which was throated for a 208 amax to barely be seated into the donut. I find it much less of a headache to simply have the throat lengthed about 0.060". Luckily I had a separate throating reamer. I played with everything- unturned loaded round started out at 0.338" in a 0.340" chamber. I turned clear down to 0.335" and took a nice cut into the shoulder. Donut was still there. The problem is the expander mandrel will not push that donut to the outside- I think it's too stiff due to the extra thickness and/or the fact that the neck/shoulder junction resists the movement. I tried neck turning, firing, then neck turning again to no avail.
I was measuring using check pins- could get rid of most of the donut using various methods, but there was always a slight bump there- less than 0.001", but I still didn't like it so I moved the throat out and seated bullets longer. I no longer care that they are there.

The problem with trying an inside the neck reamer is you'd have to have such a perfect fit in order to get rid of JUST the donut. You'd have to get a custom one ground so you could use it without having too great a reamer diamete,r taking out the neck thickness in front; or else too loose and only partially cutting the donut out. I'm talking greater than half a thousandth accuracy would have been needed for a reamer to have worked in my situation...

The method Catshooter proposed would be your only bet- I never tried it, but see it as your only hope if you can't avoid seating into the donut. Using some means to get in there and sand the donut off... It'd be tedious, so I wouldn't recommend it as opposed to reworking things in your rifle chamber to avoid the donut by seating depth.

 

[Joe Salt]

Thanks to both you guys you just saved me some more money, I have two H.G. barrels that I have to get chambered and I also have a throater that I can use. I might be using the 230 OTM's in my 300 WSM they shot very well in my L.G. and they were down into the shoulder, but it was just fire forming and there is no problem there. the throat on my reamer I believe is .226? so you tell me?

Joe Salt

 

[CatShooter]

Thanks to both you guys you just saved me some more money, I have two H.G. barrels that I have to get chambered and I also have a throater that I can use. I might be using the 230 OTM's in my 300 WSM they shot very well in my L.G. and they were down into the shoulder, but it was just fire forming and there is no problem there. the throat on my reamer I believe is .226? so you tell me?

Joe Salt

I don't know from Winchester Silly Magnums...

... REAL magnums all have belts!!

 

[dkhunt14]

The freebore for a 230 needs to be close to .280. I don't know why you would want shoot a magnum that is more accurate , more efficient, has better brass and the throat doesn't hardly move. That just doesn't make sense that anybody would want that 300 WSM. Matt

 

[Joe Salt]

Catshooter I also have one of those big Magnums its called a 308 Baer! But that little 300 WSM is a lot less finicky just easier to make work. But was thinking maybe just have one throated and see what happens!

Joe Salt

 

[CatShooter]

Catshooter I also have one of those big Magnums its called a 308 Baer! But that little 300 WSM is a lot less finicky just easier to make work. But was thinking maybe just have one throated and see what happens!

Joe Salt

Will you give it a belt for it's birthday when it grows up

 

[Patch700]

Switching to a mandrel with a cutter can solve some of these issues .

 

[asauer]

Switching to a mandrel with a cutter can solve some of these issues .

Patch have you had really good luck with those? I'm sure you have lots more experience than I... But I can't see it working very well. It'd have to be a force fit between the brass and mandrel (hence cutter) to work right and get all of the donut out of there. I would be leery of tearing the necks up as you slide the brass onto the mandrel as well.

 

[Patch700]

The mandrel is indeed a precise fit.... And yes I have had good luck using these types of mandrels particularly when using bushing dies and going through the neck turn process again after initial fire forming.

Basically it allows me to keep a handle on the donut problem from a proactive standpoint.

 

[asauer]

Interesting. Perhaps K&M and the like supply their reamer mandrels just a touch oversized from their regular? Have you measured if there is any size difference? I wrote them off as not being workable and perhaps I shouldn't have. Figured with varying brass spring back it'd be a crap shoot in effectiveness.

 

[Patch700]

They are matched to their expander mandrels , I know what you're saying as that was my original thought on the matter as well , that by using the expander mandrel it should iron out the donut to the exterior and for the most part it does.. I still see the cutter take very small and minute cuts on SOME pieces of brass and some it will not touch.

I suspect your theory that springback after expanding is not out of the question as to how the cutter would come in contact .

 

[asauer]

Well thanks- learned something new today. Hopefully thus helps the OP since I kind of derailed his thread.

 

[barefooter56]

JoeSalt,
Just turn the necks once then go to the reamer or mandrel. The donuts usually forms long before the neck thickens up. In fact, I personally have never returned a neck. Unless I didn't take enough off the first time.

 

[barefooter56]

JoeSALT & Catshooter,
L.E.Wilson has or will make custom reamers to the size you need/want. If you are not taking to much brass out of the neck you can use the reamers by hand and not have to purchase a Wilson trimmer and trimmer case holder.
Take care,

 

[CatShooter]

JoeSalt,
Just turn the necks once then go to the reamer or mandrel. The donuts usually forms long before the neck thickens up. In fact, I personally have never returned a neck. Unless I didn't take enough off the first time.

I have heard people talk about "necks getting thick" for more than 50 years. I shoot a lot, and I often get more than 40 loads from a case... and I have NEVER had a neck get thick.
If you have a neck that is 1/2" long, where does the brass come from to make 1/2" of neck thicker?

In FL sizing, if the shoulder is forced back more than a thou or two, the body CAN flow forward into the shoulder, which then pushes the shoulder into the back of the neck.

But that forms the dreaded donut, not a thick neck... and by the time your shoulder is flowing forward enough to form a donut, you have more serious problems than the donut - you have serious head space management problems.

 

[barefooter56]

Catshooter,
Agreed! But I have learned the hard way to never say "never". If you get my drift.

 

[CatShooter]

Catshooter,
Agreed! But I have learned the hard way to never say "never". If you get my drift.

Drift? What drift? We ain't got no steeeekin' drift. We don' need no steeeenkin' drift.

We gots headspace and donuts (no coffee and no drift!)

You want drift, you gotta start another thread!!